1. Field of the Invention
The present invention relates to an active radio-frequency (RF) or microwave bandage which may be used for such medical therapeutic purposes as (1) promoting improved healing of soft-tissue wounds and incisions proximate to the skin of a patient and/or (2) enhancing the efficacy of transdermal drug delivery to a patient.
2. Description of the Prior Art
It is known that pulsed RF energy is helpful in treating a variety of injuries and diseases, including promoting the healing and regrowth of both bone and soft tissue injuries, and treating osteoathritis, bursitis, and pelvic inflammatory disease. Usually, such treatments employ relatively low-frequency pulsed RF (e.g., 27.12 Mhz). In this regard, reference is made to the following articles in the literature:
1. M. J. Lobell, xe2x80x9cPulsed High Frequency and Routine Hospital Antibiotic Therapy in the Management of Pelvic Inflammatory Disease: A Preliminary Reportxe2x80x9d, Clinical Medicine, August 1962.
2. B. M. Cameron, xe2x80x9cExperimental Acceleration of Wound Healingxe2x80x9d, American Journal of Orthopedics, November 1961.
3. J. H. Goldin et al, xe2x80x9cThe Effects of Diapulse on the Healing of Wounds: A Double-Blind Randomised Controlled Trial in Manxe2x80x9d, British J. of Plastic Surgery, 34, 1981.
4. V. Barclay et al, xe2x80x9cTreatment of Various Hand Injuries by Pulsed Electromagnetic Energy (Diapulse)xe2x80x9d, Physiotherapy, vol. 69, June 1983.
5. H. Itoh et al, xe2x80x9cAccelerated Wound Healing of Pressure Ulcers by Pulsed High Peak Power Electromagnetic Energy (Diapulse)xe2x80x9d, Decubitus, February 1991.
It is also known that transdermal drug delivery may be used for local treatment of diseases of the skin, and also may be used with a small number of drugs for systemic drug delivery. The advantages of transdermal drug delivery over pills and injections include the avoidance of degradation due the gastrointestinal tract and first-pass of the liver, potential for steady or time controlled delivery of drugs, and targeted delivery to areas of diseased skin. Further, it is known that transdermal drug delivery can be enhanced by means of either pulsed DC electroporation or pulsed high power RF or microwave electroporation. In this regard, reference is made to the following articles in the literature:
6. M. R. Prausnitz et al, xe2x80x9cElectroporation of Mammalian Skin: A mechanism to Enhance Transdermal Drug Deliveryxe2x80x9d, Proc, Natl. Acad. Sci. USA, Vol. 90, pp 10504-10508, Medical Sciences, November 1993.
7. R. Vanbever et al, xe2x80x9cTransdermal Delivery of Metropol by Electroporationxe2x80x9d, Pharmaceutical Research, Vol. 11, pp. 1657-1662, Nov. 11, 1994.
8. J. E. Riviere and M. C. Heit, xe2x80x9cElectrically-Assisted Transdermal Drug Deliveryxe2x80x9d, Pharmaceutical Research, Vol. 14, pp. 6g7-6g7, June 1997.
9. C. Domenge et al, xe2x80x9cAntitumor Electrochemotherapy; New Advances in the Clinical Protocolxe2x80x9d, Cancer, Vol. 77, pp. 956-963, Mar. 1, 1996.
10. F. Sterzer, xe2x80x9cMethod for Enhancing Delivery of Chemotherapy Employing High-Frequency Force Fieldsxe2x80x9d, U.S. Pat. No. 5,368,837 Feb. 7, 1995.
Problems which now exist in the implementation of the treatments of the aforesaid prior art are that (1) Diapulse apparatus incorporates an RF generator having a permanently attached RF applicator which is in non-contacting spatial relationship with skin of a patient for radiating relatively low-frequency pulsed RF energy to the treated soft tissue underlying this skin and (2) electrical contacts have to be securely attached to the area of the patient to be treated (except for treating pressure ulcers, as described above in H. Itoh et al. (article 5)) and may have to be implanted in the patient. The discomfort to the patient of this type of implementation is particularly great in those cases in which the duration of the treatment must extend continuously over a relatively long time or must be repeated many times with a relatively short time interval between successive treatments.
Further, known in the art, are planar antenna structures that can consist of a microstrip configuration arranged in any one of various shapes of radiating elements. A microstrip planar antenna structure is fabricated from a printed circuit board by photoetching or micromachining a pre-metallized surface on one side of an insulated substrate with tightly controlled dimensions and dielectric constant in accordance with the particular shape of either a single one or an array of desired radiating elements. The proper frequency is determine by the dielectric constant of the substrate and the dimensions of each desired radiating element. Usually, the other side of the insulated substrate is also pre-metallized to provide a ground plane that functions as a reflector or a shield. Also, known in the art, is a planar antenna structure configured as a slotline antenna.
The active RF or microwave bandage of the present invention, which may employ any of various configurations of planar microstrip or slotline antenna structures, solves the implementation problem of the treatments of the aforesaid prior art by providing a practical, convenient, and effective means of implementation that would be both widely available to physicians and nurses and be much more comfortable to the patient. More specifically, the present invention is directed to an active bandage incorporating at least one pliable planar antenna that is conformable to a selected area of the skin of a patient for use in therapeutically treating soft tissue of the patient underlying the selected area with pulsed electromagnetic field (PEMF) energy of a given frequency radiated from the planar antenna. The PEMF energy is supplied to the planar antenna by means including a PEMF generator (which generator may be a miniaturized portable generator employing a battery power supply that permits the patient being treated to be ambulatory).